Selection of safety valves
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If there is backpressure on the safety valve, this factor must be taken into account when setting its test pressure; the set pressure should be reduced by the amount of backpressure. For example: the operating pressure of the container is 1. 0 MPa; the set pressure value of the safety valve is 1. 1MPa, with a back pressure of 0. 2MPa; therefore, when setting the pressure for the safety valve, the set value should be 0. 9MPa。 So when selecting a safety valve, should the set pressure be set at 1.1 MPa or 0.9 MPa?
Generally speaking, safety valves are designed to ensure the safety of equipment; their setting value should be determined based on the design pressure, rather than the operating pressure. In principle, the operating pressure must be lower than the equipment’s design pressure. I think 0.9 is more appropriate
Another important definition for a safety valve is the \"setting pressure\"; setting pressure = fixed pressure value + back pressure (fixed pressure value = setting pressure – back pressure). For safety valves that discharge independently of the back pressure, the fixed pressure value equals the setting pressure. Therefore, the fixed pressure value is related to the structure of the safety valve, whereas the setting pressure is the pressure at which the valve should open when the pressure inside the container reaches a certain level, and it is independent of the valve’s structure.
This post was last edited by Asuka Sky on 2020-3-31 15:14. So, what parameters need to be provided when selecting a safety valve? The pressure is to provide a set pressure rather than a fixed pressure, right?